Study shows prostate cancer gene 3 (PCA3) correlates with severity of prostate cancer

A study published in the May 2008 issue of the peer-reviewed Journal of Urology demonstrates that the prostate cancer gene 3 (PCA3) can be used to detect and stratify stage and grade of prostate cancer.(1)

Following recent calls for a more accurate test for the detection of prostate cancer,(2)(3) the results of this study indicate the PROGENSA(TM) PCA3 gene-based urine test may be clinically useful in identifying men with low-grade or low-volume cancer for whom active surveillance would be more appropriate than aggressive treatment, and also shows the test as a more reliable method than existing diagnostic tools such as serum-PSA.(1)

"More and more data is emerging that the PCA3 score is a useful measure to fine tune the diagnosis and classification prostate cancer," says Mr. Ranjan Thilagarajah, Consultant Urological Surgeon at Broomfield Hospital, Mid Essex Health Trust. "PROGENSA PCA3 appears to help differentiate between those that are candidates for active surveillance, and those who need aggressive treatments, making it a vital part of cutting-edge prostate cancer management. Here at Broomfield Hospital, we have already used the test in over 100 men, and hope that it will become a useful tool for more men across the country."

The study found that PCA3 scores correlate with tumour volume, and with prostatectomy Gleason scores (grade of prostate cancer). When compared to other standard measures, (including serum-PSA) the PCA3 score was found to be the best predictor of tumour volume.

In addition, PCA3 was the most successful measure for predicting low volume cancer, indicating that a PCA3 score could be beneficial when identifying men for non-aggressive therapies, such as active surveillance, for men with low-grade/low-volume cancer. Over the past 20 years, the greater utilisation and reliance on serum-PSA has led to an increase in identifying those with low grade cancer,(4)(5) therefore PROGENSA PCA3 may be a valuable tool for ensuring aggressive treatment or invasive biopsies are limited to those needing it most.

For more information about PROGENSA PCA3 and prostate cancer, please visit http://www.PCA3.org.

Notes

• A PCA3 score can be measured using PROGENSA PCA3 - a commercially available non-invasive urine test that measures the amount of PCA3 in the urine. Unlike serum-PSA, which measures the level of Prostate Specific Antigen - a substance not exclusively associated with prostate Cancer(6)(7) - PCA3 is over-expressed only by prostate cancer,(8) and therefore is seen as a more reliable diagnostic measure.
• PCA3 is a prostate-specific gene that is highly over-expressed in prostate tumours.(8) The PROGENSA(TM) PCA3 test uses Transcription Mediated Amplification (TMA) to quantify the amount of PCA3 mRNA in a patient urine sample; the higher the PCA3 score, the more likely prostate cancer is present.(9)
• Previous studies have indicated that in men who have previously had a negative biopsy, PROGENSA(TM) PCA3 can more accurately predict which men are likely to have a positive follow-up biopsy than a PSA test alone.(9)
• The prostate is a walnut-shaped gland that sits beneath the bladder and in front of the rectum. It is a fundamental part of the male reproductive system.
• Prostate cancer is the most common male cancer in the UK, with more than 34,000 men diagnosed every year, 24 per cent of all new male cancers.(10) Despite improved treatment options for prostate cancer over the past 20 years, the number of prostate cancer deaths in the UK has slightly increased. In 2005, there were 10,000 deaths in the UK, accounting for 13 per cent of all male cancer deaths.(11)

Reference List

1. Nakanishi,H. et al. (2008) PCA3 molecular urine assay correlates with prostate cancer tumor volume: implication in selecting candidates for active surveillance. J Urol 179, 1804-1809
2. Stamey,T.A. et al. (2004) The prostate specific antigen era in the United States is over for prostate cancer: what happened in the last 20 years? J Urol 172, 1297-1301
3. Bradford,T.J. et al. (2006) Molecular markers of prostate cancer. Urol Oncol. 24, 538-551
4. Loeb,S. et al. (2006) Pathological characteristics of prostate cancer detected through prostate specific antigen based screening. J Urol 175, 902-906
5. Stamey,T.A. et al. (1993) Localized prostate cancer. Relationship of tumor volume to clinical significance for treatment of prostate cancer. Cancer 71, 933-938
6. The Prostate Cancer Charity (2007) The PSA test. http://www.prostate-cancer.org.uk/info/tests_psa.asp
7. The Prostate Cancer Charity (2007) PSA background. http://www.prostate-cancer.org.uk/news/features/psa_screening.asp
8. Bussemakers,M.J. et al. (1999) DD3: a new prostate-specific gene, highly overexpressed in prostate cancer. Cancer Res 59, 5975-5979
9. Marks,L.S. et al. (2007) PCA3 molecular urine assay for prostate cancer in men undergoing repeat biopsy. Urology 69, 532-535
10. Office for National Statistics (2007) Cancer Statistics registrations: Registrations of cancer diagnosed in 2003, England (Series MB1 no.34. ed. Vol. 2005 edn)
11. Office for National Statistics (2007) Review of the Registrar General on deaths by cause, sex and age, in England and Wales, 2005. In Series DH2 no.32

http://www.gen-probe.com and http://www.PCA3.org